Fluid injector with flat sealing surface

Abstract

A fuel injector for liquefied gaseous fuel includes a housing defining a fuel path from an inlet end to an outlet end. A nozzle is disposed at the outlet end of the housing. The nozzle includes an orifice for delivering liquid fuel from the fuel injector and forms a valve seat. A valve assembly is disposed in the housing and is configured to control flow of fuel through the orifice. The valve assembly includes a reciprocating valve body that is movable within the housing between a closed position and an open position. A valve seal is held by the valve body and is formed of an elastomeric material. The valve seal includes a flat sealing surface that faces the nozzle and is configured to contact the valve seat so as to inhibit flow of fuel through the orifice.

The invention claimed is: 
     
       1. A fuel injector for liquefied gaseous fuel comprising:
 a housing defining a fuel path from an inlet end to an outlet end; 
 a nozzle disposed at the outlet end of the housing, wherein the nozzle includes an orifice for delivering liquid fuel from the fuel injector and forms a valve seat; and 
 a valve assembly disposed in the housing and configured to control flow of fuel through the orifice, the valve assembly comprising:
 a reciprocating valve body that is movable within the housing between a closed position and an open position, and 
 a valve seal held by the valve body, wherein the valve seal is formed of an elastomeric material and includes a flat sealing surface that faces the nozzle and is configured to contact the valve seat so as to inhibit flow of fuel through the orifice, 
 wherein the valve seat includes an annular upward projection that surrounds the orifice and is configured to engage the flat sealing surface of the valve seal. 
 
 
     
     
       2. The fuel injector of  claim 1 , wherein the nozzle is configured as a substantially flat plate. 
     
     
       3. The fuel injector of  claim 1 , wherein the valve seal is disposed in a cavity within the valve body. 
     
     
       4. The fuel injector of  claim 3 , wherein the valve seal includes a side surface that extends upward from the flat sealing surface. 
     
     
       5. The fuel injector of  claim 4 , wherein an interior wall of the cavity of the valve body covers the side surface of the valve seal. 
     
     
       6. The fuel injector of  claim 1 , wherein the annular upward projection is surrounded by a trough. 
     
     
       7. The fuel injector of  claim 6 , wherein the valve seat includes a support surface surrounding the trough, and wherein the support surface is configured to limit movement of the valve body. 
     
     
       8. The fuel injector of  claim 7 , wherein the upward projection extends higher than the support surface. 
     
     
       9. The fuel injector of  claim 7 , wherein a slot extends outward from the trough and is configured to maintain pressurized fuel within the trough. 
     
     
       10. The fuel injector of  claim 1 , wherein the valve body is configured to move at least 0.015 inches. 
     
     
       11. The fuel injector of  claim 1 , wherein the fuel injector includes a return path from the valve body to the inlet end. 
     
     
       12. The fuel injector of  claim 11 , wherein the return path surrounds an inlet portion of the fuel path. 
     
     
       13. A method of delivering liquefied gaseous fuel from a fuel injector, the method comprising:
 providing pressurized liquefied gaseous fuel to the fuel injector, the fuel injector comprising:
 a housing defining a fuel path from an inlet end to an outlet end, 
 a nozzle disposed at the outlet end of the housing, the nozzle forming a valve seat and including an orifice therein, and 
 a valve assembly disposed in the housing, the valve assembly including a reciprocating valve body and a valve seal held by the valve body, wherein the valve seal is formed of an elastomeric material and includes a flat sealing surface that faces the nozzle, wherein the valve seat includes an annular upward projection that surrounds the orifice, and wherein the annular upward projection presses into the flat sealing surface of the valve seal when the valve is in the closed position; 
 
 holding the valve body in a closed position in which the flat sealing surface contacts the valve seat of the nozzle so as to inhibit flow of fuel through the orifice; and 
 moving the valve body away from the nozzle so as to allow liquid fuel to pass through the orifice and be delivered from the fuel injector. 
 
     
     
       14. The method of  claim 13 , wherein the valve seal is disposed in a cavity within the valve body, wherein the valve seal includes a side surface that extends upward from the flat sealing surface, and wherein an interior wall of the cavity of the valve body covers the side surface of the valve seal. 
     
     
       15. The method of  claim 13 , wherein the valve body is moved away from the nozzle by at least 0.015 inches. 
     
     
       16. The method of  claim 13 , further comprising recirculating the fuel to the intake end along a return path so as to cool components of the fuel injector. 
     
     
       17. The method of  claim 16 , further comprising boiling the fuel within the return path. 
     
     
       18. The method of  claim 16 , wherein the return path surrounds an inlet portion of the fuel path.